Calculate temperature drop in steel pipe of district heating system (where water is a heat carrier) that is a result of heat losses through pipe wall and insulation using Minenergo Order 325 as a basis for values of heating flux.

Since Minenergo Order 325 is used as the basis for values of heating flux the calculated temperature drop may be considered as a normative temperature drop. If the actual (somehow measured) temperature drop is more than this normative temperature drop they may consider such difference to be due to extra-normative heat losses. The presence of the latter requires appropriate maintenance activities.

m325dropt(
temperature = 130,
pressure = mpa_kgf(6),
consumption = 250,
d = 700,
len = 1,
year = 1986,
insulation = 0,
laying = "underground",
beta = FALSE,
exp5k = TRUE
)

## Arguments

temperature

temperature of heat carrier (water) inside the pipe measured at the entrance of pipe, [°C]. Type: assert_double.

pressure

absolute pressure of heat carrier (water) inside the pipe, [MPa]. Type: assert_double.

consumption

amount of heat carrier (water) that is transferred by pipe during a period, [ton/hour]. Type: assert_double.

d

internal diameter of pipe, [mm]. Type: assert_double.

len

length of pipe, [m]. Type: assert_double.

year

year when the pipe is put in operation after laying or total overhaul. Type: assert_integerish.

insulation

insulation that covers the exterior of pipe:

0

no insulation

1

foamed polyurethane or analogue

2

polymer concrete

Type: assert_subset.

laying

type of pipe laying depicting the position of pipe in space:

• air,

• channel,

• room,

• tunnel,

• underground.

Type: assert_subset.

beta

should they consider additional heat losses of fittings? Type: assert_logical.

exp5k

pipe regime flag: is pipe operated more that 5000 hours per year? Type: assert_logical.

## Value

normative temperature drop at the outlet of pipe, [°C]. Type: assert_double.

## Details

The function is a simple wrapper for call of dropt with parameter flux calculated by m325nhl.

dropt for calculating temperature drop in pipe using actual heat flux values

Other Minenergo: m278hlair(), m278hlcha(), m278hlund(), m278insdata, m278inshcm(), m278soildata, m325beta(), m325nhldata, m325nhl(), m325testbench

## Examples

 stopifnot(
round(
m325dropt(
temperature = 130, year = 1968, laying = "channel", d = 700, l = 1000
), 2) == 1.37
)